526 lines
14 KiB
C
526 lines
14 KiB
C
/*
|
|
* linux/fs/hfs/extent.c
|
|
*
|
|
* Copyright (C) 1995-1997 Paul H. Hargrove
|
|
* (C) 2003 Ardis Technologies <roman@ardistech.com>
|
|
* This file may be distributed under the terms of the GNU General Public License.
|
|
*
|
|
* This file contains the functions related to the extents B-tree.
|
|
*/
|
|
|
|
#include <linux/pagemap.h>
|
|
|
|
#include "hfs_fs.h"
|
|
#include "btree.h"
|
|
|
|
/*================ File-local functions ================*/
|
|
|
|
/*
|
|
* build_key
|
|
*/
|
|
static void hfs_ext_build_key(hfs_btree_key *key, u32 cnid, u16 block, u8 type)
|
|
{
|
|
key->key_len = 7;
|
|
key->ext.FkType = type;
|
|
key->ext.FNum = cpu_to_be32(cnid);
|
|
key->ext.FABN = cpu_to_be16(block);
|
|
}
|
|
|
|
/*
|
|
* hfs_ext_compare()
|
|
*
|
|
* Description:
|
|
* This is the comparison function used for the extents B-tree. In
|
|
* comparing extent B-tree entries, the file id is the most
|
|
* significant field (compared as unsigned ints); the fork type is
|
|
* the second most significant field (compared as unsigned chars);
|
|
* and the allocation block number field is the least significant
|
|
* (compared as unsigned ints).
|
|
* Input Variable(s):
|
|
* struct hfs_ext_key *key1: pointer to the first key to compare
|
|
* struct hfs_ext_key *key2: pointer to the second key to compare
|
|
* Output Variable(s):
|
|
* NONE
|
|
* Returns:
|
|
* int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
|
|
* Preconditions:
|
|
* key1 and key2 point to "valid" (struct hfs_ext_key)s.
|
|
* Postconditions:
|
|
* This function has no side-effects */
|
|
int hfs_ext_keycmp(const btree_key *key1, const btree_key *key2)
|
|
{
|
|
__be32 fnum1, fnum2;
|
|
__be16 block1, block2;
|
|
|
|
fnum1 = key1->ext.FNum;
|
|
fnum2 = key2->ext.FNum;
|
|
if (fnum1 != fnum2)
|
|
return be32_to_cpu(fnum1) < be32_to_cpu(fnum2) ? -1 : 1;
|
|
if (key1->ext.FkType != key2->ext.FkType)
|
|
return key1->ext.FkType < key2->ext.FkType ? -1 : 1;
|
|
|
|
block1 = key1->ext.FABN;
|
|
block2 = key2->ext.FABN;
|
|
if (block1 == block2)
|
|
return 0;
|
|
return be16_to_cpu(block1) < be16_to_cpu(block2) ? -1 : 1;
|
|
}
|
|
|
|
/*
|
|
* hfs_ext_find_block
|
|
*
|
|
* Find a block within an extent record
|
|
*/
|
|
static u16 hfs_ext_find_block(struct hfs_extent *ext, u16 off)
|
|
{
|
|
int i;
|
|
u16 count;
|
|
|
|
for (i = 0; i < 3; ext++, i++) {
|
|
count = be16_to_cpu(ext->count);
|
|
if (off < count)
|
|
return be16_to_cpu(ext->block) + off;
|
|
off -= count;
|
|
}
|
|
/* panic? */
|
|
return 0;
|
|
}
|
|
|
|
static int hfs_ext_block_count(struct hfs_extent *ext)
|
|
{
|
|
int i;
|
|
u16 count = 0;
|
|
|
|
for (i = 0; i < 3; ext++, i++)
|
|
count += be16_to_cpu(ext->count);
|
|
return count;
|
|
}
|
|
|
|
static u16 hfs_ext_lastblock(struct hfs_extent *ext)
|
|
{
|
|
int i;
|
|
|
|
ext += 2;
|
|
for (i = 0; i < 2; ext--, i++)
|
|
if (ext->count)
|
|
break;
|
|
return be16_to_cpu(ext->block) + be16_to_cpu(ext->count);
|
|
}
|
|
|
|
static void __hfs_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
|
|
{
|
|
int res;
|
|
|
|
hfs_ext_build_key(fd->search_key, inode->i_ino, HFS_I(inode)->cached_start,
|
|
HFS_IS_RSRC(inode) ? HFS_FK_RSRC : HFS_FK_DATA);
|
|
res = hfs_brec_find(fd);
|
|
if (HFS_I(inode)->flags & HFS_FLG_EXT_NEW) {
|
|
if (res != -ENOENT)
|
|
return;
|
|
hfs_brec_insert(fd, HFS_I(inode)->cached_extents, sizeof(hfs_extent_rec));
|
|
HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
|
|
} else {
|
|
if (res)
|
|
return;
|
|
hfs_bnode_write(fd->bnode, HFS_I(inode)->cached_extents, fd->entryoffset, fd->entrylength);
|
|
HFS_I(inode)->flags &= ~HFS_FLG_EXT_DIRTY;
|
|
}
|
|
}
|
|
|
|
void hfs_ext_write_extent(struct inode *inode)
|
|
{
|
|
struct hfs_find_data fd;
|
|
|
|
if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY) {
|
|
hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
|
|
__hfs_ext_write_extent(inode, &fd);
|
|
hfs_find_exit(&fd);
|
|
}
|
|
}
|
|
|
|
static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
|
|
u32 cnid, u32 block, u8 type)
|
|
{
|
|
int res;
|
|
|
|
hfs_ext_build_key(fd->search_key, cnid, block, type);
|
|
fd->key->ext.FNum = 0;
|
|
res = hfs_brec_find(fd);
|
|
if (res && res != -ENOENT)
|
|
return res;
|
|
if (fd->key->ext.FNum != fd->search_key->ext.FNum ||
|
|
fd->key->ext.FkType != fd->search_key->ext.FkType)
|
|
return -ENOENT;
|
|
if (fd->entrylength != sizeof(hfs_extent_rec))
|
|
return -EIO;
|
|
hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfs_extent_rec));
|
|
return 0;
|
|
}
|
|
|
|
static inline int __hfs_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
|
|
{
|
|
int res;
|
|
|
|
if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY)
|
|
__hfs_ext_write_extent(inode, fd);
|
|
|
|
res = __hfs_ext_read_extent(fd, HFS_I(inode)->cached_extents, inode->i_ino,
|
|
block, HFS_IS_RSRC(inode) ? HFS_FK_RSRC : HFS_FK_DATA);
|
|
if (!res) {
|
|
HFS_I(inode)->cached_start = be16_to_cpu(fd->key->ext.FABN);
|
|
HFS_I(inode)->cached_blocks = hfs_ext_block_count(HFS_I(inode)->cached_extents);
|
|
} else {
|
|
HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
|
|
HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static int hfs_ext_read_extent(struct inode *inode, u16 block)
|
|
{
|
|
struct hfs_find_data fd;
|
|
int res;
|
|
|
|
if (block >= HFS_I(inode)->cached_start &&
|
|
block < HFS_I(inode)->cached_start + HFS_I(inode)->cached_blocks)
|
|
return 0;
|
|
|
|
hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
|
|
res = __hfs_ext_cache_extent(&fd, inode, block);
|
|
hfs_find_exit(&fd);
|
|
return res;
|
|
}
|
|
|
|
static void hfs_dump_extent(struct hfs_extent *extent)
|
|
{
|
|
int i;
|
|
|
|
dprint(DBG_EXTENT, " ");
|
|
for (i = 0; i < 3; i++)
|
|
dprint(DBG_EXTENT, " %u:%u", be16_to_cpu(extent[i].block),
|
|
be16_to_cpu(extent[i].count));
|
|
dprint(DBG_EXTENT, "\n");
|
|
}
|
|
|
|
static int hfs_add_extent(struct hfs_extent *extent, u16 offset,
|
|
u16 alloc_block, u16 block_count)
|
|
{
|
|
u16 count, start;
|
|
int i;
|
|
|
|
hfs_dump_extent(extent);
|
|
for (i = 0; i < 3; extent++, i++) {
|
|
count = be16_to_cpu(extent->count);
|
|
if (offset == count) {
|
|
start = be16_to_cpu(extent->block);
|
|
if (alloc_block != start + count) {
|
|
if (++i >= 3)
|
|
return -ENOSPC;
|
|
extent++;
|
|
extent->block = cpu_to_be16(alloc_block);
|
|
} else
|
|
block_count += count;
|
|
extent->count = cpu_to_be16(block_count);
|
|
return 0;
|
|
} else if (offset < count)
|
|
break;
|
|
offset -= count;
|
|
}
|
|
/* panic? */
|
|
return -EIO;
|
|
}
|
|
|
|
static int hfs_free_extents(struct super_block *sb, struct hfs_extent *extent,
|
|
u16 offset, u16 block_nr)
|
|
{
|
|
u16 count, start;
|
|
int i;
|
|
|
|
hfs_dump_extent(extent);
|
|
for (i = 0; i < 3; extent++, i++) {
|
|
count = be16_to_cpu(extent->count);
|
|
if (offset == count)
|
|
goto found;
|
|
else if (offset < count)
|
|
break;
|
|
offset -= count;
|
|
}
|
|
/* panic? */
|
|
return -EIO;
|
|
found:
|
|
for (;;) {
|
|
start = be16_to_cpu(extent->block);
|
|
if (count <= block_nr) {
|
|
hfs_clear_vbm_bits(sb, start, count);
|
|
extent->block = 0;
|
|
extent->count = 0;
|
|
block_nr -= count;
|
|
} else {
|
|
count -= block_nr;
|
|
hfs_clear_vbm_bits(sb, start + count, block_nr);
|
|
extent->count = cpu_to_be16(count);
|
|
block_nr = 0;
|
|
}
|
|
if (!block_nr || !i)
|
|
return 0;
|
|
i--;
|
|
extent--;
|
|
count = be16_to_cpu(extent->count);
|
|
}
|
|
}
|
|
|
|
int hfs_free_fork(struct super_block *sb, struct hfs_cat_file *file, int type)
|
|
{
|
|
struct hfs_find_data fd;
|
|
u32 total_blocks, blocks, start;
|
|
u32 cnid = be32_to_cpu(file->FlNum);
|
|
struct hfs_extent *extent;
|
|
int res, i;
|
|
|
|
if (type == HFS_FK_DATA) {
|
|
total_blocks = be32_to_cpu(file->PyLen);
|
|
extent = file->ExtRec;
|
|
} else {
|
|
total_blocks = be32_to_cpu(file->RPyLen);
|
|
extent = file->RExtRec;
|
|
}
|
|
total_blocks /= HFS_SB(sb)->alloc_blksz;
|
|
if (!total_blocks)
|
|
return 0;
|
|
|
|
blocks = 0;
|
|
for (i = 0; i < 3; extent++, i++)
|
|
blocks += be16_to_cpu(extent[i].count);
|
|
|
|
res = hfs_free_extents(sb, extent, blocks, blocks);
|
|
if (res)
|
|
return res;
|
|
if (total_blocks == blocks)
|
|
return 0;
|
|
|
|
hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
|
|
do {
|
|
res = __hfs_ext_read_extent(&fd, extent, cnid, total_blocks, type);
|
|
if (res)
|
|
break;
|
|
start = be16_to_cpu(fd.key->ext.FABN);
|
|
hfs_free_extents(sb, extent, total_blocks - start, total_blocks);
|
|
hfs_brec_remove(&fd);
|
|
total_blocks = start;
|
|
} while (total_blocks > blocks);
|
|
hfs_find_exit(&fd);
|
|
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* hfs_get_block
|
|
*/
|
|
int hfs_get_block(struct inode *inode, sector_t block,
|
|
struct buffer_head *bh_result, int create)
|
|
{
|
|
struct super_block *sb;
|
|
u16 dblock, ablock;
|
|
int res;
|
|
|
|
sb = inode->i_sb;
|
|
/* Convert inode block to disk allocation block */
|
|
ablock = (u32)block / HFS_SB(sb)->fs_div;
|
|
|
|
if (block >= HFS_I(inode)->fs_blocks) {
|
|
if (block > HFS_I(inode)->fs_blocks || !create)
|
|
return -EIO;
|
|
if (ablock >= HFS_I(inode)->alloc_blocks) {
|
|
res = hfs_extend_file(inode);
|
|
if (res)
|
|
return res;
|
|
}
|
|
} else
|
|
create = 0;
|
|
|
|
if (ablock < HFS_I(inode)->first_blocks) {
|
|
dblock = hfs_ext_find_block(HFS_I(inode)->first_extents, ablock);
|
|
goto done;
|
|
}
|
|
|
|
mutex_lock(&HFS_I(inode)->extents_lock);
|
|
res = hfs_ext_read_extent(inode, ablock);
|
|
if (!res)
|
|
dblock = hfs_ext_find_block(HFS_I(inode)->cached_extents,
|
|
ablock - HFS_I(inode)->cached_start);
|
|
else {
|
|
mutex_unlock(&HFS_I(inode)->extents_lock);
|
|
return -EIO;
|
|
}
|
|
mutex_unlock(&HFS_I(inode)->extents_lock);
|
|
|
|
done:
|
|
map_bh(bh_result, sb, HFS_SB(sb)->fs_start +
|
|
dblock * HFS_SB(sb)->fs_div +
|
|
(u32)block % HFS_SB(sb)->fs_div);
|
|
|
|
if (create) {
|
|
set_buffer_new(bh_result);
|
|
HFS_I(inode)->phys_size += sb->s_blocksize;
|
|
HFS_I(inode)->fs_blocks++;
|
|
inode_add_bytes(inode, sb->s_blocksize);
|
|
mark_inode_dirty(inode);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int hfs_extend_file(struct inode *inode)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
u32 start, len, goal;
|
|
int res;
|
|
|
|
mutex_lock(&HFS_I(inode)->extents_lock);
|
|
if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks)
|
|
goal = hfs_ext_lastblock(HFS_I(inode)->first_extents);
|
|
else {
|
|
res = hfs_ext_read_extent(inode, HFS_I(inode)->alloc_blocks);
|
|
if (res)
|
|
goto out;
|
|
goal = hfs_ext_lastblock(HFS_I(inode)->cached_extents);
|
|
}
|
|
|
|
len = HFS_I(inode)->clump_blocks;
|
|
start = hfs_vbm_search_free(sb, goal, &len);
|
|
if (!len) {
|
|
res = -ENOSPC;
|
|
goto out;
|
|
}
|
|
|
|
dprint(DBG_EXTENT, "extend %lu: %u,%u\n", inode->i_ino, start, len);
|
|
if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks) {
|
|
if (!HFS_I(inode)->first_blocks) {
|
|
dprint(DBG_EXTENT, "first extents\n");
|
|
/* no extents yet */
|
|
HFS_I(inode)->first_extents[0].block = cpu_to_be16(start);
|
|
HFS_I(inode)->first_extents[0].count = cpu_to_be16(len);
|
|
res = 0;
|
|
} else {
|
|
/* try to append to extents in inode */
|
|
res = hfs_add_extent(HFS_I(inode)->first_extents,
|
|
HFS_I(inode)->alloc_blocks,
|
|
start, len);
|
|
if (res == -ENOSPC)
|
|
goto insert_extent;
|
|
}
|
|
if (!res) {
|
|
hfs_dump_extent(HFS_I(inode)->first_extents);
|
|
HFS_I(inode)->first_blocks += len;
|
|
}
|
|
} else {
|
|
res = hfs_add_extent(HFS_I(inode)->cached_extents,
|
|
HFS_I(inode)->alloc_blocks -
|
|
HFS_I(inode)->cached_start,
|
|
start, len);
|
|
if (!res) {
|
|
hfs_dump_extent(HFS_I(inode)->cached_extents);
|
|
HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
|
|
HFS_I(inode)->cached_blocks += len;
|
|
} else if (res == -ENOSPC)
|
|
goto insert_extent;
|
|
}
|
|
out:
|
|
mutex_unlock(&HFS_I(inode)->extents_lock);
|
|
if (!res) {
|
|
HFS_I(inode)->alloc_blocks += len;
|
|
mark_inode_dirty(inode);
|
|
if (inode->i_ino < HFS_FIRSTUSER_CNID)
|
|
set_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags);
|
|
set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
|
|
sb->s_dirt = 1;
|
|
}
|
|
return res;
|
|
|
|
insert_extent:
|
|
dprint(DBG_EXTENT, "insert new extent\n");
|
|
hfs_ext_write_extent(inode);
|
|
|
|
memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
|
|
HFS_I(inode)->cached_extents[0].block = cpu_to_be16(start);
|
|
HFS_I(inode)->cached_extents[0].count = cpu_to_be16(len);
|
|
hfs_dump_extent(HFS_I(inode)->cached_extents);
|
|
HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW;
|
|
HFS_I(inode)->cached_start = HFS_I(inode)->alloc_blocks;
|
|
HFS_I(inode)->cached_blocks = len;
|
|
|
|
res = 0;
|
|
goto out;
|
|
}
|
|
|
|
void hfs_file_truncate(struct inode *inode)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
struct hfs_find_data fd;
|
|
u16 blk_cnt, alloc_cnt, start;
|
|
u32 size;
|
|
int res;
|
|
|
|
dprint(DBG_INODE, "truncate: %lu, %Lu -> %Lu\n", inode->i_ino,
|
|
(long long)HFS_I(inode)->phys_size, inode->i_size);
|
|
if (inode->i_size > HFS_I(inode)->phys_size) {
|
|
struct address_space *mapping = inode->i_mapping;
|
|
void *fsdata;
|
|
struct page *page;
|
|
int res;
|
|
|
|
/* XXX: Can use generic_cont_expand? */
|
|
size = inode->i_size - 1;
|
|
res = pagecache_write_begin(NULL, mapping, size+1, 0,
|
|
AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata);
|
|
if (!res) {
|
|
res = pagecache_write_end(NULL, mapping, size+1, 0, 0,
|
|
page, fsdata);
|
|
}
|
|
if (res)
|
|
inode->i_size = HFS_I(inode)->phys_size;
|
|
return;
|
|
} else if (inode->i_size == HFS_I(inode)->phys_size)
|
|
return;
|
|
size = inode->i_size + HFS_SB(sb)->alloc_blksz - 1;
|
|
blk_cnt = size / HFS_SB(sb)->alloc_blksz;
|
|
alloc_cnt = HFS_I(inode)->alloc_blocks;
|
|
if (blk_cnt == alloc_cnt)
|
|
goto out;
|
|
|
|
mutex_lock(&HFS_I(inode)->extents_lock);
|
|
hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
|
|
while (1) {
|
|
if (alloc_cnt == HFS_I(inode)->first_blocks) {
|
|
hfs_free_extents(sb, HFS_I(inode)->first_extents,
|
|
alloc_cnt, alloc_cnt - blk_cnt);
|
|
hfs_dump_extent(HFS_I(inode)->first_extents);
|
|
HFS_I(inode)->first_blocks = blk_cnt;
|
|
break;
|
|
}
|
|
res = __hfs_ext_cache_extent(&fd, inode, alloc_cnt);
|
|
if (res)
|
|
break;
|
|
start = HFS_I(inode)->cached_start;
|
|
hfs_free_extents(sb, HFS_I(inode)->cached_extents,
|
|
alloc_cnt - start, alloc_cnt - blk_cnt);
|
|
hfs_dump_extent(HFS_I(inode)->cached_extents);
|
|
if (blk_cnt > start) {
|
|
HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
|
|
break;
|
|
}
|
|
alloc_cnt = start;
|
|
HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
|
|
HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
|
|
hfs_brec_remove(&fd);
|
|
}
|
|
hfs_find_exit(&fd);
|
|
mutex_unlock(&HFS_I(inode)->extents_lock);
|
|
|
|
HFS_I(inode)->alloc_blocks = blk_cnt;
|
|
out:
|
|
HFS_I(inode)->phys_size = inode->i_size;
|
|
HFS_I(inode)->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
|
|
inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
|
|
mark_inode_dirty(inode);
|
|
}
|